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Good size crystal of pleonast, a variety of spinel containing Fe²⁺. It shows complex crystalline forms of the octahedron and combinations of the octahedron with the dodecahedron or, more rarely, with those of the cube. A museum size piece, very rare to get.
Very elongated quartz crystal, very rich in faces, with excellent transparence. Rock crystal...
Highly lustrous, rounded faces, jet-black spinel octahedrons included in a calcite matrix from this less well-known locality. Crystals of this size and quality are rare from here and this is a fine and good sized specimen from the E. Nicolau (Barcelona) Collection.
Good size garnet crystal belonging to the almandine-spessartine series, usually with a predominance of the first one. The analyzes indicate the presence of Fe and Mn, with traces of Mg. These specimens were identified as pyrope (magnesium aluminosilicate), but the analytical results do not indicate this.
Group of garnet crystals belonging to the almandine-spessartine series, usually with a predominance of the first one. The analyzes indicate the presence of Fe and Mn, with traces of Mg. These specimens were identified as pyrope (magnesium aluminosilicate), but the analytical results do not indicate this.
Group of garnet crystals belonging to the almandine-spessartine series, usually with a predominance of the first one. The analyzes indicate the presence of Fe and Mn, with traces of Mg. These specimens were identified as pyrope (magnesium aluminosilicate), but the analytical results do not indicate this.
Group of garnet crystals belonging to the almandine-spessartine series, usually with a predominance of the first one. The analyzes indicate the presence of Fe and Mn, with traces of Mg. These specimens were identified as pyrope (magnesium aluminosilicate), but the analytical results do not indicate this.
Interesting quartz crystals with several inclusions of "petroleum" and other hydrocarbons. The petroleum in these quartz crystals from Madagascar appear brownish yellow and, as with many other petroleum inclusions in quartz, they react to long and short wave UV light with yellow to blue fluorescence. Microscopic examination reveals numerous complex fluid inclusions containing obvious brownish yellow petroleum, gas bubbles presumed to be methane, dark solids of what is likely asphaltite, and a colorless immiscible liquid that could be probably water. Microscopic inclusions in quartz are of particular interest to the collector due to their spectacular UV reaction (gia.edu).
Interesting scepter quartz crystals with several inclusions of "petroleum" and other hydrocarbons. The petroleum in these quartz crystals from Madagascar appear brownish yellow and, as with many other petroleum inclusions in quartz, they react to long and short wave UV light with yellow to blue fluorescence. Microscopic examination reveals numerous complex fluid inclusions containing obvious brownish yellow petroleum, gas bubbles presumed to be methane, dark solids of what is likely asphaltite, and a colorless immiscible liquid that could be probably water. Microscopic inclusions in quartz are of particular interest to the collector due to their spectacular UV reaction (gia.edu).
Interesting scepter quartz crystals with several inclusions of "petroleum" and other hydrocarbons. The petroleum in these quartz crystals from Madagascar appear brownish yellow and, as with many other petroleum inclusions in quartz, they react to long and short wave UV light with yellow to blue fluorescence. Microscopic examination reveals numerous complex fluid inclusions containing obvious brownish yellow petroleum, gas bubbles presumed to be methane, dark solids of what is likely asphaltite, and a colorless immiscible liquid that could be probably water. Microscopic inclusions in quartz are of particular interest to the collector due to their spectacular UV reaction (gia.edu).
Interesting scepter quartz crystals with several inclusions of "petroleum" and other hydrocarbons. The petroleum in these quartz crystals from Madagascar appear brownish yellow and, as with many other petroleum inclusions in quartz, they react to long and short wave UV light with yellow to blue fluorescence. Microscopic examination reveals numerous complex fluid inclusions containing obvious brownish yellow petroleum, gas bubbles presumed to be methane, dark solids of what is likely asphaltite, and a colorless immiscible liquid that could be probably water. Microscopic inclusions in quartz are of particular interest to the collector due to their spectacular UV reaction (gia.edu).
Interesting scepter quartz crystals with several inclusions of "petroleum" and other hydrocarbons. The petroleum in these quartz crystals from Madagascar appear brownish yellow and, as with many other petroleum inclusions in quartz, they react to long and short wave UV light with yellow to blue fluorescence. Microscopic examination reveals numerous complex fluid inclusions containing obvious brownish yellow petroleum, gas bubbles presumed to be methane, dark solids of what is likely asphaltite, and a colorless immiscible liquid that could be probably water. Microscopic inclusions in quartz are of particular interest to the collector due to their spectacular UV reaction (gia.edu).
Rich group of grandidierite crystals, on matrix. Unusually well defined and aerial for the species. Brilliant, translucent and with an intense uniform bluish-green color. We can observe prismatic crystals with terminal faces. A sample of great quality for this rare nesosilicate. With the label of the collector.
Grandidierite was discovered by the French mineralogist, Alfred Lacroix in 1902 and named after French explorer and naturalist Alfred Grandidier (1836-1912), who wrote the great natural history book: "L'Histoire physique, naturelle et politique de Madagascar". The first reported locality for the species is at the cliffs of Andrahomana, on the southern coast of Madagascar. The species is a magnesium, iron, aluminum borosilicate and although it has been found in multiple localities around the world, it's still considered exceptionally rare, especially in gem quality material (mindat).
Monazite-(Ce) crystal, floater, rich in faces, with luster and intense brown color. Nowadays finding specimens with this quality is not easy.
These specimens have been analyzed, indicating that cerium is predominant, and that it is accompanied by other REEs such as lanthanum and neodymium, together with thorium, which gives it some radioactivity. We will send the results and label to the buyer.
Very good monazite-(Ce) crystal, floater, rich in faces, with luster and light brown color. It is accompanied by a cubic crystal of columbite-tantalite embeded in. These specimens have been analyzed, indicating that cerium is predominant, and that it is accompanied by other REEs such as lanthanum and neodymium, together with thorium, which gives it some radioactivity. We will send the results and label to the buyer.
Excellent monazite-(Ce) crystal, totally floater, rich in faces, with luster and intense brown color. Nowadays finding specimens with this quality is not easy.
These specimens have been analyzed, indicating that cerium is predominant, and that it is accompanied by other REEs such as lanthanum and neodymium, together with thorium, which gives it some radioactivity. We will send the results and label to the buyer.
Hambergite is a rare mineral species, a beryllium hydroxyborate, which occurs in the tourmaline pegmatites of Anjanabonoina. This sample shows us a group of crystals of exceptional size and quality, flattened and with well-defined terminations. Transparent to translucent, with brilliance. This mineral is usually found as single crystals, rarely on matrix, and less with this size. A museum piece.
A huge size crystal of betafite showing defined octahedral faces (triangular) and developed dodecahedral ones. Very interesting for its crystallography and species. An oldie, classic and representative for the species.
Although the term betafite was discredited in 2010, many of us still are using this term to define this mineral when we see it. Our specimen is an uranium, calcium, titanium and niobium/tantalum oxide with radioactive activity. Currently the betafite is included as a variety within the pyrochlore supergroup. As a note, the rich uranium term has been only found in the Moon (oxyuranobetafite).
Group of hyaline quartz crystals, very transparent, brilliant, with complex shapes due to polycrystalline and window growths. With orange inclusions. Very aesthetic and interesting specimens from a new Malagasy locality.
Curious parallel growth of quartz crystals in scepter. A very aesthetic miniature of a new locality in Madagascar.
Group of hyaline quartz crystals, very brilliant, one of them more developed and showing the scepter growth stands out. With polycrystalline growths. An aesthetic novelty from Madagascar.
Aesthetic quartz specimen, very transparent and with orange inclusions. It shows a very curious window growths and some facets of the rhombohedron. These specimens come from a little-known locality. Really interesting.
Group of doubly terminated quartz crystals, very transparent and with orange inclusions. With prisms and terminal faces with very evident polycrystalline and window growths. These specimens come from a new not well-known locality. Very aesthetic and pure brilliance.
A good size specimen showing a group of cubic fluorite crystals, between translucent and transparent, with an intense green color with delicate dichroism under sunlight. The crystals are interpenetrated and show geometric color zoning and interesting and esthetic inclusions of white color. Very fluorescent under LW-UV and SW-UV. New locality for fluorite in Madagascar.
A good size specimen showing a group of cubic fluorite crystals, between translucent and transparent, with an intense green color with delicate dichroism under sunlight. The crystals are interpenetrated and show geometric color zoning and interesting and esthetic inclusions of white color. Very fluorescent under LW-UV and SW-UV. New locality for fluorite in Madagascar.